op atlanta



May 26, 1931.

H. SEE

CORRUGATED CONDUI T Filed Deo.l

M 1 VEA/TOR.

ATTORNEYJ Patented May 26, 1931 UNITED STATES. PATENT OFFICE HOWARDSEE,OF ATLANTA, GEORGIA, ASSIGNOR T THE DIXIE C'UITE'BT MAL COMPANY, OFATLANTA, GEORGIA, A. CORPORATION DI' GEORGIA COBRUGATED CONDUITApplication led. December 27, 1927. Serial No. 242,945.

My invention relates to the formation of tubes, pipes or culverts, whichI will refer to generally as conduits formed of corrugated sheet metal,and coated with a lling for the In the construction of a corrugatedsheet metal conduit, metal sheets which are previously corrugated areformed into cylinders, with the meeting edges lapped and riveted,

forming a lateral seam, and the sections made. up from the individualsheets are joined tol 5 gether, usually by leaving the terminal of thelateral seam open, and expanding one end of each section to lap the endof another section, whereupon rivets are used to unite the two sections,thus forming a circumferential 0 seam. The corrugations in the resultingconduit are circumferential thereof, and the seams are both lateral orlengthwise, for each section, and circumferential between each ction.The conduits so formed are usually built in such lengths as will be easyto ship,

and a series of them are set together in the field or on the job toprovide for the desired length of conduit structure. Various types of]oints are provided for the conduit pieces,

which do not particularly concern this invention."

It is the object of this'invention to provide a coating process and aconduit of the type noted, which is so coated that all corrugations areilled, leaving a smooth interior to the conduit, and in which all seamsare fully covered,

thus permitting use of the conduits for purposes where considerablepressure is required.

It is thus the object of my invention to pro- 40 vide a conduitstructure having the advantage of great strength under load andincirpensiveness of manufacture, inherentin the corrugated sheet metalpipe, together with the smooth interior and resistance to internal gjpressure of the cast iron pipe. Also, the coating material may be suchas will protect the interior of the conduit against corrosive anderosive iniuences.

The new conduits may be emplo ed as culverts, and also for sewage lines,igh pres-'50 sure water lines, siphons, pen stock, and other purposeswhere a leak-proof, corrosion-proof, and pressure-proof element isrequired.

I accomplish my objects by that construction of conduit, made by thatcoating and filling process, of which typical and illustrative instanceswill be hereinafter specifically -pointed out and claimed.

Figure 1 is a side elevation illustrating a mechanism for coating andfilling a corrugated pipe according to my invention.

Figure 2 is a section taken on the line 2-2 of Figure 1. f Figure 3 is alongitudinal section taken through a conduit formed accordingto myinvention.

Referring first to the corrugated conduit element, I have indicated at'.1 a conduit formed of sections 2. Each section is formed of alengthwise corrugated sheet bent into a cylinder and riveted in alateral seam 3. The sections each formed of one sheet are lapped in a`circumferential manner, and riveted to form a conduit ofthe lengthdesired, the seams of circumferential nature being indicated at 4. Asshown in Figure 3, I ll the interior of the corrugated conduit so formedwith a suitablebituminous or sim 1 lar composition, so that thecorrugations 1n the conduit are filled up, leaving a smoothcylindrical'interior. The filling is shown at 5, and it will be lnotedthat it not only smooths the interior ofthe conduit, but also completelycloses all the seams therein.

l The problem of providing aninterior coating of a corrugated vsheetmetal conduit, which will be smooth and adherent, and will not crack orbreak or deteriorate under chemical action, or the influences of theweather, is not gg o'ov conduit lining whichwill resist erosive actionand remain-sucientl flexible to remain in place when the conduit isdeformed, as in a fill of earth.

By my invention I provide for a combination of centrifugal molding andgravity flow in a corrugated conduit, which exactly serves my purpose.

As a typical, simple mechanism for providin the said conduit fillingandrcoating, I provi e a kettle 6, in which is maintained a heatliquefied bitumen, which bitumen flows from the tank through a suitablespout 7. A platform or base 8 rests 0n a jack 9 at the spout end of theapparatus so that the slant of the base can be adjusted. A motor 10 maybe used for power, which motor has a pinion 11 thereon that drives agear 12 having a shaft la arranged on a standard 13, central of theframe. 'Ihe shaft has a spider 15 thereon, to the peripheral portions ofwhich is secured a corrugated cylinder 16, corresponding to the shape ofthe conduit to be coated. There will be a corrugated band 17 of a sizeto fit the conduit 1 and the cylinder or drum 16.`

As indicated, the band is set over the end of the conduit to be filledand the drum, and clamped in place. A series of holes in the balg willnormally be provided as indicated a" 'Ihe conduit 1, resting on a standformed of rollers 19 mounted on the base, is engaged and held to thedrum so as to revolve when the motor is driven.

With the conduit at a slant, and in rotary motion, the liquid bitumen ispermitted to How out of the vspout into the upper en d of the conduit,using a valve to control the flow as at 20. I t Will solidify fairlyquickly because the condult is not heated and 1s kept in motion, and assoon as the first corrugation fills up the bitumen will flow onto theneXt corrugation and fill it, and s0 on, until the bitumen has filledall of the corrugations and starts to come out through the holes in theclamping band.

The spout or the kettle is withdrawn slightly s0 as to permit thefilling of the corrugations at the upper end of the conduit, which, forconvenience, are not filled at the outset of the process. A

The bitumen is then stopped and the conduit revolved until there issufficient solidity, due to cooling, so that the coating will remain inplace.

If additional thickness is desired for the filling, it can be added,using proper slant and speed to give an even coating.

The speed of revolution will be controlled to give the proper coatingeffect without any diliiculty, and the type of drive, the mechanism usedto support and revolve the conduit, can be varied at will. The essentialis that the operator should be able to control the speed of revolutionand the pitch or slant at which the conduit is held durin the fillingprocess, and the rate of flow o the filling material.

To hasten the cooling and solidification of the filling, water can beflown into the filled conduit, and will form a film within it, due tothe centrifugal action. Also, the conduit may be lowered to a horizontalposition during the cooling.

As a coating material I prefer a rubbery bitumen having considerableadhesiveness such as is found in blown oils. Other bitumens than blownoils can be used, however.

The centrifugal action will cause the bitumen to flow out through anycracks and thus ll the seams, as indicated at 21, and naturally thesolidified coating will entirely seal the interior of the conduitvBituminous materials of paint like quality so far as adhesiveness isconcerned, are desirable, this being the case in the instance of theblown oils heretofore referred to.

Finely divided mineral matter in insucient quantities to materiallyaffect the flow of the filling material during the process described maybe employed to give a harder quality to the filling without destroyingits adhesiveness.

The usefulness of the product of my invention for the purposes noted atthe outset of this specification will be evident without further remark.

I-Iaving thus described my invention, what I claim as new and desire tosecure by .Iletters Patent, is

1. A process for providing a smooth in terior for corrugated sheet metalcondults, which consists in rotating the conduit while holding the sameat a slant, and at the same time pouring heat liquefied bituminousmaterial into the upper end of said conduit, whereby gravity andcentrifugal force act simultaneously to provide a smooth interiorcoating that fills the corrugations.

2. A process for providing a smooth interior for corrugated sheet metalconduits, which consists in rotating the conduit While holding the sameat a slant, and at the same time pouring heat liquefied bituminousmaterial into the upper end of said conduit, whereby gravity andcentrifugal force act simultaneously to provide a smooth interiorcoating that fills the corrugations, and ro tating the c'onduit afterthe filling is comllti plete, until cooling action has solidified thelling. 3. A. process for roviding a smooth interior for corrugate sheetmetal conduits, lwhich consists in rotating the conduit while holdingthe same at a. slantl and at the same time pouring heat liquefiedbituminous material into the upper end of said conduit, whereby gravityand centrifugal force act simultaneously to provide a smooth interiorcoating that ills the corrugations, and rotating the conduit after thefilling is complete, until cooling action has solidied the filling,Water being owed into the conduit during u the final rotation thereof toaid the cooling.

' HOWARD SEE.

